Table 1. Study features of 11 included studies.

Reference	Study type	Location	Study period	Age range	Case (participation)/control (participation)	Type of source	Assessment of measures
Nordstrom 1997 [27]	Case-control	Sweden	1987-1992	---	121(--)/484(--)	National population registry	Mailed questionnaire; telephone interview
Hughes 2004 [28]	Case-control	Australia	2000-2001	20-74	704(85%)/694(61%)	Electoral rolls	Self-administered questionnaire; telephone interview
Smedby 2005 [29]	Case-control	Denmark and Sweden	1999-2002	18-74	3055(81%)/3187(71%)	Population	Telephone interview
Morales 2006 [37]	Case-control	Europe	1995-1997	35-69	76(91.6%)/2094(--)	Population registries or electoral rolls	Face-to-face interview
Tavani 2006 [30]	Case-control	Northern Italy	1985-1997	18-79	446(>97%)/1295(>97%)	Patients hospitalized with other conditions	Personal interview
Karipidis 2007 [31]	Case-control	Australia	2000-2001	20-74	694(85%)/694(61%)	Population, electoral rolls	Self-administered questionnaire; telephone interview
Weihkopf 2007 [32]	Case-control	Germany		18-80	589(87.4%)/589(51.4%)	Population registers	Face-to-face interview
Zhang 2007 [33]	Case-control	USA	1996-2000	21-84	601(72%)/706(--)	Population	In person interview
Boffetta 2008 [34]	Case-control	Europe	1998-2003	>17	1518(88%)/2124(81% in hospital controls, 52% in population controls)	Population registers; Patients hospitalized with other conditions	In person interview
Wong 2012 [35]	Case-control	Singapore	2004-2008	>18	541(--)/830(--)	Patients hospitalized with other conditions	Face-to-face interview

Reference	Study type	Location	Follow-up years	Case/cohort	Cohort source	Assessment of measures
Hakansson 2001 [36]	Cohort	Sweden	1971-1993	484/323860	Nationwide occupational health service program of the Swedish construction industry	Used data files from nationwide occupational health service organization